Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (35 commits)
  sched, cputime: Introduce thread_group_times()
  sched, cputime: Cleanups related to task_times()
  Revert "sched, x86: Optimize branch hint in __switch_to()"
  sched: Fix isolcpus boot option
  sched: Revert 498657a478c60be092208422fefa9c7b248729c2
  sched, time: Define nsecs_to_jiffies()
  sched: Remove task_{u,s,g}time()
  sched: Introduce task_times() to replace task_{u,s}time() pair
  sched: Limit the number of scheduler debug messages
  sched.c: Call debug_show_all_locks() when dumping all tasks
  sched, x86: Optimize branch hint in __switch_to()
  sched: Optimize branch hint in context_switch()
  sched: Optimize branch hint in pick_next_task_fair()
  sched_feat_write(): Update ppos instead of file->f_pos
  sched: Sched_rt_periodic_timer vs cpu hotplug
  sched, kvm: Fix race condition involving sched_in_preempt_notifers
  sched: More generic WAKE_AFFINE vs select_idle_sibling()
  sched: Cleanup select_task_rq_fair()
  sched: Fix granularity of task_u/stime()
  sched: Fix/add missing update_rq_clock() calls
  ...

1 files changed, 174 insertions, 96 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 6ae2739b8f1..aa31244caa9 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -535,14 +535,12 @@ struct rq {
         #define CPU_LOAD_IDX_MAX 5
         unsigned long cpu_load[CPU_LOAD_IDX_MAX];
 #ifdef CONFIG_NO_HZ
-        unsigned long last_tick_seen;
         unsigned char in_nohz_recently;
 #endif
         /* capture load from *all* tasks on this cpu: */
         struct load_weight load;
         unsigned long nr_load_updates;
         u64 nr_switches;
-        u64 nr_migrations_in;
 
         struct cfs_rq cfs;
         struct rt_rq rt;
@@ -591,6 +589,8 @@ struct rq {
 
         u64 rt_avg;
         u64 age_stamp;
+        u64 idle_stamp;
+        u64 avg_idle;
 #endif
 
         /* calc_load related fields */
@@ -772,7 +772,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
         if (!sched_feat_names[i])
                 return -EINVAL;
 
-        filp->f_pos += cnt;
+        *ppos += cnt;
 
         return cnt;
 }
@@ -2017,6 +2017,7 @@ void kthread_bind(struct task_struct *p, unsigned int cpu)
         }
 
         spin_lock_irqsave(&rq->lock, flags);
+        update_rq_clock(rq);
         set_task_cpu(p, cpu);
         p->cpus_allowed = cpumask_of_cpu(cpu);
         p->rt.nr_cpus_allowed = 1;
@@ -2078,7 +2079,6 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 #endif
         if (old_cpu != new_cpu) {
                 p->se.nr_migrations++;
-                new_rq->nr_migrations_in++;
 #ifdef CONFIG_SCHEDSTATS
                 if (task_hot(p, old_rq->clock, NULL))
                         schedstat_inc(p, se.nr_forced2_migrations);
@@ -2115,6 +2115,7 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
          * it is sufficient to simply update the task's cpu field.
          */
         if (!p->se.on_rq && !task_running(rq, p)) {
+                update_rq_clock(rq);
                 set_task_cpu(p, dest_cpu);
                 return 0;
         }
@@ -2376,14 +2377,15 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
         task_rq_unlock(rq, &flags);
 
         cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
-        if (cpu != orig_cpu)
+        if (cpu != orig_cpu) {
+                local_irq_save(flags);
+                rq = cpu_rq(cpu);
+                update_rq_clock(rq);
                 set_task_cpu(p, cpu);
-
+                local_irq_restore(flags);
+        }
         rq = task_rq_lock(p, &flags);
 
-        if (rq != orig_rq)
-                update_rq_clock(rq);
-
         WARN_ON(p->state != TASK_WAKING);
         cpu = task_cpu(p);
 
@@ -2440,6 +2442,17 @@ out_running:
 #ifdef CONFIG_SMP
         if (p->sched_class->task_wake_up)
                 p->sched_class->task_wake_up(rq, p);
+
+        if (unlikely(rq->idle_stamp)) {
+                u64 delta = rq->clock - rq->idle_stamp;
+                u64 max = 2*sysctl_sched_migration_cost;
+
+                if (delta > max)
+                        rq->avg_idle = max;
+                else
+                        update_avg(&rq->avg_idle, delta);
+                rq->idle_stamp = 0;
+        }
 #endif
 out:
         task_rq_unlock(rq, &flags);
@@ -2545,6 +2558,7 @@ static void __sched_fork(struct task_struct *p)
 void sched_fork(struct task_struct *p, int clone_flags)
 {
         int cpu = get_cpu();
+        unsigned long flags;
 
         __sched_fork(p);
 
@@ -2581,7 +2595,10 @@ void sched_fork(struct task_struct *p, int clone_flags)
 #ifdef CONFIG_SMP
         cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
 #endif
+        local_irq_save(flags);
+        update_rq_clock(cpu_rq(cpu));
         set_task_cpu(p, cpu);
+        local_irq_restore(flags);
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
         if (likely(sched_info_on()))
@@ -2848,14 +2865,14 @@ context_switch(struct rq *rq, struct task_struct *prev,
          */
         arch_start_context_switch(prev);
 
-        if (unlikely(!mm)) {
+        if (likely(!mm)) {
                 next->active_mm = oldmm;
                 atomic_inc(&oldmm->mm_count);
                 enter_lazy_tlb(oldmm, next);
         } else
                 switch_mm(oldmm, mm, next);
 
-        if (unlikely(!prev->mm)) {
+        if (likely(!prev->mm)) {
                 prev->active_mm = NULL;
                 rq->prev_mm = oldmm;
         }
@@ -3018,15 +3035,6 @@ static void calc_load_account_active(struct rq *this_rq)
 }
 
 /*
- * Externally visible per-cpu scheduler statistics:
- * cpu_nr_migrations(cpu) - number of migrations into that cpu
- */
-u64 cpu_nr_migrations(int cpu)
-{
-        return cpu_rq(cpu)->nr_migrations_in;
-}
-
-/*
  * Update rq->cpu_load[] statistics. This function is usually called every
  * scheduler tick (TICK_NSEC).
  */
@@ -4126,7 +4134,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
         unsigned long flags;
         struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
 
-        cpumask_setall(cpus);
+        cpumask_copy(cpus, cpu_online_mask);
 
         /*
          * When power savings policy is enabled for the parent domain, idle
@@ -4289,7 +4297,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
         int all_pinned = 0;
         struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
 
-        cpumask_setall(cpus);
+        cpumask_copy(cpus, cpu_online_mask);
 
         /*
          * When power savings policy is enabled for the parent domain, idle
@@ -4429,6 +4437,11 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
         int pulled_task = 0;
         unsigned long next_balance = jiffies + HZ;
 
+        this_rq->idle_stamp = this_rq->clock;
+
+        if (this_rq->avg_idle < sysctl_sched_migration_cost)
+                return;
+
         for_each_domain(this_cpu, sd) {
                 unsigned long interval;
 
@@ -4443,8 +4456,10 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
                 interval = msecs_to_jiffies(sd->balance_interval);
                 if (time_after(next_balance, sd->last_balance + interval))
                         next_balance = sd->last_balance + interval;
-                if (pulled_task)
+                if (pulled_task) {
+                        this_rq->idle_stamp = 0;
                         break;
+                }
         }
         if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
                 /*
@@ -5046,8 +5061,13 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
         p->gtime = cputime_add(p->gtime, cputime);
 
         /* Add guest time to cpustat. */
-        cpustat->user = cputime64_add(cpustat->user, tmp);
-        cpustat->guest = cputime64_add(cpustat->guest, tmp);
+        if (TASK_NICE(p) > 0) {
+                cpustat->nice = cputime64_add(cpustat->nice, tmp);
+                cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp);
+        } else {
+                cpustat->user = cputime64_add(cpustat->user, tmp);
+                cpustat->guest = cputime64_add(cpustat->guest, tmp);
+        }
 }
 
 /*
@@ -5162,60 +5182,86 @@ void account_idle_ticks(unsigned long ticks)
  * Use precise platform statistics if available:
  */
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
-cputime_t task_utime(struct task_struct *p)
+void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 {
-        return p->utime;
+        *ut = p->utime;
+        *st = p->stime;
 }
 
-cputime_t task_stime(struct task_struct *p)
+void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 {
-        return p->stime;
+        struct task_cputime cputime;
+
+        thread_group_cputime(p, &cputime);
+
+        *ut = cputime.utime;
+        *st = cputime.stime;
 }
 #else
-cputime_t task_utime(struct task_struct *p)
+
+#ifndef nsecs_to_cputime
+# define nsecs_to_cputime(__nsecs)      nsecs_to_jiffies(__nsecs)
+#endif
+
+void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 {
-        clock_t utime = cputime_to_clock_t(p->utime),
-                total = utime + cputime_to_clock_t(p->stime);
-        u64 temp;
+        cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime);
 
         /*
          * Use CFS's precise accounting:
          */
-        temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
+        rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
 
         if (total) {
-                temp *= utime;
+                u64 temp;
+
+                temp = (u64)(rtime * utime);
                 do_div(temp, total);
-        }
-        utime = (clock_t)temp;
+                utime = (cputime_t)temp;
+        } else
+                utime = rtime;
+
+        /*
+         * Compare with previous values, to keep monotonicity:
+         */
+        p->prev_utime = max(p->prev_utime, utime);
+        p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime));
 
-        p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
-        return p->prev_utime;
+        *ut = p->prev_utime;
+        *st = p->prev_stime;
 }
 
-cputime_t task_stime(struct task_struct *p)
+/*
+ * Must be called with siglock held.
+ */
+void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 {
-        clock_t stime;
+        struct signal_struct *sig = p->signal;
+        struct task_cputime cputime;
+        cputime_t rtime, utime, total;
 
-        /*
-         * Use CFS's precise accounting. (we subtract utime from
-         * the total, to make sure the total observed by userspace
-         * grows monotonically - apps rely on that):
-         */
-        stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
-                        cputime_to_clock_t(task_utime(p));
+        thread_group_cputime(p, &cputime);
 
-        if (stime >= 0)
-                p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
+        total = cputime_add(cputime.utime, cputime.stime);
+        rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
 
-        return p->prev_stime;
-}
-#endif
+        if (total) {
+                u64 temp;
 
-inline cputime_t task_gtime(struct task_struct *p)
-{
-        return p->gtime;
+                temp = (u64)(rtime * cputime.utime);
+                do_div(temp, total);
+                utime = (cputime_t)temp;
+        } else
+                utime = rtime;
+
+        sig->prev_utime = max(sig->prev_utime, utime);
+        sig->prev_stime = max(sig->prev_stime,
+                              cputime_sub(rtime, sig->prev_utime));
+
+        *ut = sig->prev_utime;
+        *st = sig->prev_stime;
 }
+#endif
 
 /*
  * This function gets called by the timer code, with HZ frequency.
@@ -6175,22 +6221,14 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
         BUG_ON(p->se.on_rq);
 
         p->policy = policy;
-        switch (p->policy) {
-        case SCHED_NORMAL:
-        case SCHED_BATCH:
-        case SCHED_IDLE:
-                p->sched_class = &fair_sched_class;
-                break;
-        case SCHED_FIFO:
-        case SCHED_RR:
-                p->sched_class = &rt_sched_class;
-                break;
-        }
-
         p->rt_priority = prio;
         p->normal_prio = normal_prio(p);
         /* we are holding p->pi_lock already */
         p->prio = rt_mutex_getprio(p);
+        if (rt_prio(p->prio))
+                p->sched_class = &rt_sched_class;
+        else
+                p->sched_class = &fair_sched_class;
         set_load_weight(p);
 }
 
@@ -6935,7 +6973,7 @@ void show_state_filter(unsigned long state_filter)
         /*
          * Only show locks if all tasks are dumped:
          */
-        if (state_filter == -1)
+        if (!state_filter)
                 debug_show_all_locks();
 }
 
@@ -7740,6 +7778,16 @@ early_initcall(migration_init);
 
 #ifdef CONFIG_SCHED_DEBUG
 
+static __read_mostly int sched_domain_debug_enabled;
+
+static int __init sched_domain_debug_setup(char *str)
+{
+        sched_domain_debug_enabled = 1;
+
+        return 0;
+}
+early_param("sched_debug", sched_domain_debug_setup);
+
 static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
                                   struct cpumask *groupmask)
 {
@@ -7826,6 +7874,9 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
         cpumask_var_t groupmask;
         int level = 0;
 
+        if (!sched_domain_debug_enabled)
+                return;
+
         if (!sd) {
                 printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
                 return;
@@ -7905,6 +7956,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
 
 static void free_rootdomain(struct root_domain *rd)
 {
+        synchronize_sched();
+
         cpupri_cleanup(&rd->cpupri);
 
         free_cpumask_var(rd->rto_mask);
@@ -8045,6 +8098,7 @@ static cpumask_var_t cpu_isolated_map;
 /* Setup the mask of cpus configured for isolated domains */
 static int __init isolated_cpu_setup(char *str)
 {
+        alloc_bootmem_cpumask_var(&cpu_isolated_map);
         cpulist_parse(str, cpu_isolated_map);
         return 1;
 }
@@ -8881,7 +8935,7 @@ static int build_sched_domains(const struct cpumask *cpu_map)
         return __build_sched_domains(cpu_map, NULL);
 }
 
-static struct cpumask *doms_cur;        /* current sched domains */
+static cpumask_var_t *doms_cur; /* current sched domains */
 static int ndoms_cur;           /* number of sched domains in 'doms_cur' */
 static struct sched_domain_attr *dattr_cur;
                                 /* attribues of custom domains in 'doms_cur' */
@@ -8903,6 +8957,31 @@ int __attribute__((weak)) arch_update_cpu_topology(void)
         return 0;
 }
 
+cpumask_var_t *alloc_sched_domains(unsigned int ndoms)
+{
+        int i;
+        cpumask_var_t *doms;
+
+        doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL);
+        if (!doms)
+                return NULL;
+        for (i = 0; i < ndoms; i++) {
+                if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) {
+                        free_sched_domains(doms, i);
+                        return NULL;
+                }
+        }
+        return doms;
+}
+
+void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms)
+{
+        unsigned int i;
+        for (i = 0; i < ndoms; i++)
+                free_cpumask_var(doms[i]);
+        kfree(doms);
+}
+
 /*
  * Set up scheduler domains and groups. Callers must hold the hotplug lock.
  * For now this just excludes isolated cpus, but could be used to
@@ -8914,12 +8993,12 @@ static int arch_init_sched_domains(const struct cpumask *cpu_map)
 
         arch_update_cpu_topology();
         ndoms_cur = 1;
-        doms_cur = kmalloc(cpumask_size(), GFP_KERNEL);
+        doms_cur = alloc_sched_domains(ndoms_cur);
         if (!doms_cur)
-                doms_cur = fallback_doms;
-        cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map);
+                doms_cur = &fallback_doms;
+        cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map);
         dattr_cur = NULL;
-        err = build_sched_domains(doms_cur);
+        err = build_sched_domains(doms_cur[0]);
         register_sched_domain_sysctl();
 
         return err;
@@ -8969,19 +9048,19 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
  * doms_new[] to the current sched domain partitioning, doms_cur[].
  * It destroys each deleted domain and builds each new domain.
  *
- * 'doms_new' is an array of cpumask's of length 'ndoms_new'.
+ * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
  * The masks don't intersect (don't overlap.) We should setup one
  * sched domain for each mask. CPUs not in any of the cpumasks will
  * not be load balanced. If the same cpumask appears both in the
  * current 'doms_cur' domains and in the new 'doms_new', we can leave
  * it as it is.
  *
- * The passed in 'doms_new' should be kmalloc'd. This routine takes
- * ownership of it and will kfree it when done with it. If the caller
- * failed the kmalloc call, then it can pass in doms_new == NULL &&
- * ndoms_new == 1, and partition_sched_domains() will fallback to
- * the single partition 'fallback_doms', it also forces the domains
- * to be rebuilt.
+ * The passed in 'doms_new' should be allocated using
+ * alloc_sched_domains.  This routine takes ownership of it and will
+ * free_sched_domains it when done with it. If the caller failed the
+ * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
+ * and partition_sched_domains() will fallback to the single partition
+ * 'fallback_doms', it also forces the domains to be rebuilt.
  *
  * If doms_new == NULL it will be replaced with cpu_online_mask.
  * ndoms_new == 0 is a special case for destroying existing domains,
@@ -8989,8 +9068,7 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
  *
  * Call with hotplug lock held
  */
-/* FIXME: Change to struct cpumask *doms_new[] */
-void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
+void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
                              struct sched_domain_attr *dattr_new)
 {
         int i, j, n;
@@ -9009,40 +9087,40 @@ void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
         /* Destroy deleted domains */
         for (i = 0; i < ndoms_cur; i++) {
                 for (j = 0; j < n && !new_topology; j++) {
-                        if (cpumask_equal(&doms_cur[i], &doms_new[j])
+                        if (cpumask_equal(doms_cur[i], doms_new[j])
                             && dattrs_equal(dattr_cur, i, dattr_new, j))
                                 goto match1;
                 }
                 /* no match - a current sched domain not in new doms_new[] */
-                detach_destroy_domains(doms_cur + i);
+                detach_destroy_domains(doms_cur[i]);
 match1:
                 ;
         }
 
         if (doms_new == NULL) {
                 ndoms_cur = 0;
-                doms_new = fallback_doms;
-                cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map);
+                doms_new = &fallback_doms;
+                cpumask_andnot(doms_new[0], cpu_online_mask, cpu_isolated_map);
                 WARN_ON_ONCE(dattr_new);
         }
 
         /* Build new domains */
         for (i = 0; i < ndoms_new; i++) {
                 for (j = 0; j < ndoms_cur && !new_topology; j++) {
-                        if (cpumask_equal(&doms_new[i], &doms_cur[j])
+                        if (cpumask_equal(doms_new[i], doms_cur[j])
                             && dattrs_equal(dattr_new, i, dattr_cur, j))
                                 goto match2;
                 }
                 /* no match - add a new doms_new */
-                __build_sched_domains(doms_new + i,
+                __build_sched_domains(doms_new[i],
                                         dattr_new ? dattr_new + i : NULL);
 match2:
                 ;
         }
 
         /* Remember the new sched domains */
-        if (doms_cur != fallback_doms)
-                kfree(doms_cur);
+        if (doms_cur != &fallback_doms)
+                free_sched_domains(doms_cur, ndoms_cur);
         kfree(dattr_cur);       /* kfree(NULL) is safe */
         doms_cur = doms_new;
         dattr_cur = dattr_new;
@@ -9364,10 +9442,6 @@ void __init sched_init(void)
 #ifdef CONFIG_CPUMASK_OFFSTACK
         alloc_size += num_possible_cpus() * cpumask_size();
 #endif
-        /*
-         * As sched_init() is called before page_alloc is setup,
-         * we use alloc_bootmem().
-         */
         if (alloc_size) {
                 ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
 
@@ -9522,6 +9596,8 @@ void __init sched_init(void)
                 rq->cpu = i;
                 rq->online = 0;
                 rq->migration_thread = NULL;
+                rq->idle_stamp = 0;
+                rq->avg_idle = 2*sysctl_sched_migration_cost;
                 INIT_LIST_HEAD(&rq->migration_queue);
                 rq_attach_root(rq, &def_root_domain);
 #endif
@@ -9571,7 +9647,9 @@ void __init sched_init(void)
         zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
         alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
 #endif
-        zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
+        /* May be allocated at isolcpus cmdline parse time */
+        if (cpu_isolated_map == NULL)
+                zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
 #endif /* SMP */
 
         perf_event_init();